The present invention relates to a method and a device for capturing the SO2 present in the gases originating from cells for the industrial production of aluminium by igneous electrolysis. The method is implemented over a group of at least two reactors passed through in parallel by a gas stream and supplied at least partly in series with a sorption agent of the powder material type, in particular alumina particles, capable of adsorbing effluents present in the gas stream by placing the sorption agent in contact with the gas stream.